The SL-8 rifle was first presented to the public at IWA-98 show, and manufacturing commenced late in 1998. This rifle was designed by famous German arms-making company Heckler und Koch GmbH on the basis of its 5,56mm NATO G36 assault rifle, which is a standard issue rifle of German and Spanish armies. SL stands for (Self-Loading in English or Selbst-Lade in German), 8 is the consecutive index of civilian rifles made by HK. HK SL-8 rifle can be used for hunting small game, but it is also suitable for para-military training, security and self-defense use, and practical sport shooting. Because of modular design, SL-8 can be modified to a number of variations, which will accept reduced 10-round capacity or standard 30-round capacity magazines, various handguards, sighs etc. This rifle is accurate, comfortable to use and very reliable, but also somewhat expensive, like most other products of Heckler und Koch.

Heckler-Koch SL-8 rifle is gas operated, semi-automatic weapon. It uses patented short-stroke gas piston system, located above the barrel, which is very reliable and requires minimal maintenance. Barrel locking is achieved by rotary bolt with seven radial lugs, which engages barrel extension and thus relieves polymer receiver from most of the firing stress. Cocking handle design is copied from G36 assault rifle, and when not in use, folding cocking handle lies in line with the gun at the top of receiver. For cocking, it can be swung to either side, and once released, it will straighten itself back automatically. Feed system has bolt hold-open device. Polymer stock is of modular design, and forearm and magazine housing can be easily replaced; basic disassembly requires no special tools. Manual safety is ambidextrous and is conveniently located above the grip. Shoulder stock is of thumb-hole design, has adjustable cheek rest and can be adjusted for length of pull using special rubber pads. Standard sighting equipment includes a detachable sight rail, attached to the top of receiver. In basic configuration, this rail hosts protected front sight and fully adjustable flip-up rear sight. A variety of optional optical sights can be installed on the rail between front and rear open sights. Alternatively, a raised Picatinny-type rail or G36 / G36E carrying handle with integral sights (red-dot, low-magnification telescope or both) can be installed in place of standard sight rail. Feed is using detachable box magazines. Because magazine housing is detachable, rifle can be easily adapted for a variety of magazine types - proprietary 10-round magazines, G36-type 30-round magazines or Ar-15 / M16 type 30-round magazines.